Machine for bending metal sheets



Aug- 3, 1954 J. c. GERSTER MACHINE EORBENDING METAL SHEETS 2 Sheets-Sheet 1 Filed May 19, 1952 Iii/e )ra y /qt o 101066..

2 Sheets-Sheet 2 J. C. GERSTER I MACHINE FOR BENDING METAL SHEETS Aug. 3, 1954 Filed May 19, 1952 Patented Aug. 3, 1954 TENT QFFHCE MACHINE FOR BENDING METAL SHEETS Johann Christian Gcrster, Gelterkinden, Switzerland Application May 19, 1952, Serial N0. 288,706

Claims priority, application Switzerland May 25, 1951 17 Claims. l

My invention has for its object a method for the bending of metal sheets, in particular for the execution of conically bent sheets and possibly also of cylindrical sheets and it also covers a machine for carrying out said method.

The bending of a sheet metal into conical shape has been performed hitherto in ordinary rolling works by means of cylindrical or conical rolls or else on presses so as to provide the bending by means of a succession of operative steps.

In the case of the use of cylindrical rolls, such operations are very `inaccurate and expensive. On the other hand, rolling by means of conical rolls leads to an improvement inasmuch as it is possible to roll without difficulty to a predetermined specied conical angle. However if it is desired to modify this angle, it is necessary to provide, when it is desired to obtain satisfactory work, a plurality of sets of rolls, which also leads to an increase in the cost price.

The object of my invention is to remove these drawbacks. The method according to the invention as intended for the bending of metal sheets consists in that the metal sheet that is to be bent is subjected to the action of a bending beam that reciprocates with reference to a cooperating stationary bending beam, While the modifications of the angle of curvature are obtained by modifying the extent of movement imparted to the moving beam, the metal sheet that is to be bent being guided in a manner such that it is submitted to the action of the movable beam along a straight line that registers with the generating line of the hollow member that it is desired to obtain.

The machine for the execution of this method includes a stationary beam and a cooperating beam submitted to a reciprocating movement with reference thereto, the metal sheet that is to be bent being introduced between the two beams by means of suitable guiding and shifting members in a manner such that it is subjected to pressure by the movable beam along a pressure line registering with the location of the generating line of the hollow member that is being executed while means are provided for adjusting the extent of movement of the movable beam.

The accompanying drawings illustrate a preferred embodiment of my improved machine. In said drawings:

Fig. 1 is a side View thereof.

Fig. 2 is a view from above of the same machine. v

Fig. 3 is a View in the direction of the arrow A of Fig. 2.

Fig. 4 is a cross-section on a larger scale through line IV-IV of Fig. 1.

The machine illustrated in the drawings includes a frame or upright I provided with bearings 2 and 3 wherein is removably carried a stationary vertical bending beam i engaging said bearings through terminal .pivots la and Lib; one of said bearings 3 may be shifted vertically through the agency of an arm 5 sliding inside a slideway t while the other bearing 2 forms a rocking bearing that is adapted to revolve round a horizontal axis whereby it may be rocked, when the upper bearing 3 of the beam 4 has been shifted upwardly, so as to assume the position illustrated in dot and dash lines in Fig. l.

In front of the beam 4 is provided a movable beam or plate 'I connected with a control member so that it may be shifted to and fro in a horizontal direction as illustrated by the arrows B. For this purpose, the beam 'l is suspended inside the upright I by means of links 9 vand it is pivotally connected with a further link 8 which constitutes with the lever arm II a toggle lever the pivotal axis of which is shifted upwardly and downwardly by means of a crank mechanism that is disclosed with further detail hereinafter. Instead of the movable beam J being carried by means of links, sai-d movable beam might as well be guided with reference to the stationary beam d by means of horizontal slideways. The lever arm Ii is rigid with an eccentric Illa carried by a shaft I0 revolubly supported by the upright I. This shaft It may be angularly shifted by hand by means of a flywheel, not illustrated, or the like, provided at one of its ends and it may also be held fast in the desired position by means that are not illustrated.

The lever arm I I is Ibent downwardly at the end connecting it with the link 8 and it is pivotally connected through this bent end with a crank arm I2 the other end or" which is rigid with an eccentric I3a carried by a shaft I3.

Said shaft I3 is carried on the other hand in eccentric bores provided in bushings revolubly carried by the upright I, each of said bushings being provided with an outwardly toothed flange. These outer series of teeth I4 mesh with pinions It that are keyed to a shaft I5 that is also revolubly carried by the upright I. A rotation of the shaft l5 as produced by a handwheel or the like non-illustrated part, produces a rotation of the bushings and consequently a shifting of the shaft I3. This allows adjusting the extent of movement of the movable reciprocating beam '1,

3 said movement being obtained as disclosed hereinafter.

A rotation of the shaft I provides on the other hand a shifting towards the right or towards the left of the path thus defined through the angular adjustment of the shaft i5, which latter adjustment is essential .when it is desired to bend metal sheets of different thicknesses.

To one end of the shaft i3 is keyed a discl provided with a diametrically extending groove l1. Inside this groove is adjustably positioned the pin i9 of a crank arm 2B the other end oi which is pivotally secured to the control lever of a unidirectional coupling' 2l. The latter is designed in a manner such that an angular movement of the crank arm 2a in the direction of `one of the arrows C causes a shaft 22a, connected with the coupling through a set of bevel pinions 22, to revolve while said shaft is not actuated when the crank arm is shifted angularly in the opposite direction. l A further set or" bevel'wheels 23 provides for the transmission of this interlmitten-t motion to a shaft 2M which carries at its upper end a roller '2da that serves for the progression of the vmetal sheet (see Fig. 4) through cooperation withV the auxiliary roller 2Gb. These rollers Elia andf2'4b are located in the path of the metal sheet just underneath the narrow gap defined between the beams #i and l, these4 rollers lying substantially midway across uthe passage formed by said gap. The rollerA Zta that urges the metal sheet forwardly is slightly at an angle with reference to the cooperating roller 24h whereby the metal sheet is constantly urged downwardly.

' The operation of the bending beams il and 'l is apparent fronrinspection of Fig. fi. Both the stationary and the movable beam are provided with a jaw designated by the reference number lo or 7c. The movable jaw lc is provided with two raised operative sections Td between which there projects during operation a raised section 4d on the opposite jaw @le so that the metal sheet B may be bent between said two operative sections 'edq The jaw f-c of the stationary beam 4 is provided with a further raised section 4e forming a bearing that keeps the metal sheet in its normal direction as it enters the operating Jaws.

' The sheet bending mechanism and the forward movement of the sheet are controlled through the electric motor 25 which is connected by means' of a belt' 2G with a belt pulley 2 keyed to the shaft i3.

' 28 designates in Figs. 2' and 3 a carrier table facing the bending beams and provided with guiding rollers 30. Said table is advantageously adapted to rock round a horizontal transverse -vaxis .and may be secured in any desired angular position corresponding to the desired angle to lbe given to the sheet cone. One oi these pivoted positions of said table 28 is shown in dot and dash lines in Fig. 1. A plurality of sheet-engaging rolls 3lis provided with a View to guiding vertically the metal sheet to be bent, said rolls 3l being slidably secured to vertical. supports 32 so that they may be adjusted vertically through a sliding of the actual roll-carriers in the dovetailed guideways `33 on said supports '32. This possibility of vertical adjustment provided for the -rolls 3l allows adjusting the location of the latter in a manner such that the sheet sections l fed over said rolls may be bent by the movable beam 1 or by the jawlc thereon along a come 4 pression line corresponding to a generating line of the conical surface to be obtained.

The above described machine allows a subst-antial increase in the speed of manufacture with a view to obtaining conical sheet members. As the entering sheet sections B (Figp) cut into the shape of segments of an annulus run over adjustable rolls to correspond to any angle to be given to the cone, it is possible to ensure reliably and permanently an accurate position of the "'metal sheet along the line of engagement between the two bending beams while the lines '.allowing the checking of the diameter of the cone on the carrier table 28 ensure a. continuous and accurate*checking of the proper execution of the :conical sheet.

`What I claim is:

1. A machine for bending sheet metal into a conical shape, comprising a stationary beam, a second beam substantially parallel with the first beam and deiining therewith a narrow gap,

means for urging the second beam into a reciprocating -stationary beam, means foradjusting .the ammovement towards and away from the plitude of said reciprocating movement and means for Vfeeding a metal sheet having an arcuate bottom edge between the two beams-in a manner such that the line of engagement thereof with the two' beams to either side thereof. co-

incides at any moment with the location of a second beam to move-towards and away from lthe stationary beam, means for urging the second beam into a reciprocating movement along the path thus allowed towards and away from the stationary beam,V means for feeding a metal sheet havingan'arcuate bottom edge into the gap between the-two beams in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any moment with the location on the sheet oi a, generating line of the cone to be obtained and means for adjusting the extent of movement of the second beam with reference to the stationary beam and the location ofr the path corresponding to said movement.

3. A machine for bending sheet metal into a conical shape comprising a stationary beam, a second beam substantially parallel with'the iirst Vvbeam and dening-therewith a narrow gap,

means guiding the second Vbeam in aV direction Vperpendicular tothe general direction of said gap to allow said second beam to move towards and away from the stationary beam, means for feeding a metal sheethavingV an arcuate bottom vedge into the gap between the two beams in a manconical shape comprising a stationary beam, a

second beam substantially parallel with the-lirst :beam` and deningrtherewith a narrow gap, an

eccentric, means for making same revolverand a transmission connecting the eccentric with the second beam to constrain the latter to assume a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of said reciprocating movement and means for feeding a metal sheet having an arcuate bottom edge between the two beams in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any moment with the location of a generating line of the cone to be obtained.

5. A machine for bending sheet metal into a conical shape comprising a stationary beam, a second beam substantially parallel with the rst beam and defining therewith a narrow gap, an eccentric, means for making same revolve and a transmission including a toggle joint connecting the eccentric with the second beam to constrain the latter to assume a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of said reciprocating movement and means for feeding a metal sheet having an arcuate bottom edge between the two beams in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any moment with the location of a generating line of the cone to be obtained.

6. A machine for bending sheet metal into a conical shape, comprising a stationary beam, a second beam substantially parallel with the first beam and defining therewith a narrow gap, an eccentric, means for making same revolve and a transmission including a toggle joint pivotally secured at one end to the second beam, a second eccentric to which the other end of the toggle joint is pivotally secured, a shaft revolubly carrying last-mentioned second eccentric and a crank arm carried by first eccentric and engaging an intermediate point of the toggle lever to constrain the beam to assume a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of said reciprocating movement and means for feeding a metal sheet having an arcuate bottom edge between the two beams in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any moment with the location of a generating line of the cone to be obtained.

7. A machine for bending sheet metal into a conical shape comprising a stationary beam, a second beam substantially parallel with the first beam and defining therewith a narrow gap, an eccentric, means for making same revolve :and a transmission including a toggle joint pivotally secured at one end to the second beam, a second eccentric to which the other end of the toggle joint is pivotally secured, an angularly adjustable shaft the axis of which is stationary and on which the second eccentric is revolubly carried, the angular adjustment of the shaft being adapted to shift the operative stroke of the first end of y the toggle joint by a corresponding extent and a crank arm carried by rst eccentric and engaging an intermediate point of the toggle lever to constrain the beam to assume a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of said reciprocating movement and means for feeding a metal sheet having an arcuate bottom edge between the two beams in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any momentwith the location of a'generatinglineof the cone to be obtained.

8. A machine for bending sheet metal into a conical shape comprising a stationary beam, a second beam substantially parallel with the first beam and defining therewith a narrow gap, an eccentric, a shaft carrying the eccentric, bushes provided with eccentric bores in which are revolubly carried the ends of said eccentric shaft, said bushes including an outer series of teeth, a control shaft parallel with the eccentric shaft, stationary bearings revolubly carrying last mentioned control shaft, means controlling the angular setting of said control shaft, two pinions of equal diameters rigid with the last mentioned control shaft and meshing with the teeth on the corresponding bushes to angularly shift the eccentric, means for making same revolve and a transmission connecting the eccentric with the second beam to constrain the latter to assume a reciprocating movement towards and away from the stationary beam, the magnitude of the stroke of the second beam being adjusted by the shifting of the eccentric, and means for feeding a metal sheet having an arcuate bottom edge between the two beams in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any moment with the location of a generating line of the cone to be obtained.

9. A machine for bending sheet metal into a conical shape, comprising a stationary beam, a second beam substantially parallel with the rst beam and defining therewith a narrow gap, an electric motor controlling the second beam and constraining it to assume a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of the movement towards the stationary beam as transmitted by the motor to the second beam, a unidirectional clutch controlled by the electric motor and means whereby said unidirectional clutch urges intermittently the sheet to be bent forwardly into the gap between the two beams in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any moment with the location of a generating line of the cone to be obtained, said sheet having an arcuate bottom edge.

10. A machine for bending sheet metal into a conical shape, comprising a stationary beam including a lateral projecting section, a second beam substantially parallel with the first beam and deiining therewith a narrow gap and including a jaw facing the projecting section on the stationary beam and provided with two projecting sheet-engaging sections to either side of said iirst mentioned projecting section, means for urging the second beam into a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of said reciprocating movement and means for feeding a metal sheet having an arcuate bottom edge between the projecting sections on the two beams in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any moment with the location of a generating line of the cone to be obtained. l

11. A machine for bending sheet metal into a conical shape, comprising a stationary beam including a lateral projecting section, a second beam substantially parallel with the rst beam and defining therewith a narrow gap and including a jaw facing the projecting section on the stationary beam and provided with two project- -ing sheet-engaging sectionstd either siden of said first mentioned projectingV section` and a further projection adapted to engage the sheet to be bent to prevent a further bending thereof before it reaches ther justmentioned projecting sections, means for urging `the second beam into a reciprocating movement towards and away from the stationary beam, means for` adjusting the amplitude of said reciprocating movement and means for feeding a metal sheet having an arcuate bottom edge over the further projection towards the-first mentionedprojecting sections in a manner such that the line of engagement thereof with the two beams to either side thereof coincides at any moment with the location of a generating line of the'cone tobe obtained.

12. A machine for bending sheet metal into a conical shape, comprising a stationary beam, a second beam substantially parallel with the first beam and defining therewith a narrow gap, means for urging the second beam into a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of said reciprocating movement and means for feeding a metal sheet having an arcuate bottom edge between the two beams in a manner such that theline of engagement thereof with the two beams to either side thereof coincides at any moment with the location of a generating line of the cone to be obtained, a carrier table extending laterally of the beam system, and rollers adapted to revolve round axes lying in a plane parallel with the surface of the table and adapted to carry the lower .edges of the sheets as they pass out of the gap between the beams.

13. A machine for bending sheet metal into a conical shape, comprising a stationary beam, a second beam substantially parallel with the first beam and defining therewith aY narrow gap, means for urging the Second beam into a reciprocating movement towardsand away from the stationary beam, means for ,adjusting the amplitude of said reciprocating movement, 'means for feeding a metal sheet having an arcuate bottom edge between the-two beams in a manner such that the line of engagement thereof with the two kbeams to eitherV side thereof coincides at any moment with the location of a generating line of the cone to Vbe obtained, a carrier table Yextending laterally of the beam system, means for shifting angularly said table round an axis lying in a plane parallel with the general direction of the gap between the two beams, means for securing the table in-any selected angular direction with reference to-last mentioned axis, and rollers adapted to revolve round axes lying in a plane parallel with the surface of the table and adapted to carry the lower edges of the sheets as they pass out of the gap between the beams.

14. A machine for bending sheet metal into a conical shape, comprising a stationarybeam, a second beam substantially parallel with the first beam and defining therewith a narow gap, means for urging the second beam into a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of said reciprocatingmovement and means for feeding a metal sheet having anv arcuate bottom. edge between the two beams in a manner such -that the line -of engagement-thereof ,with the two beams to either side thereofcoincides atnany v-moment with .the locationiof a 4generatingrline of the.cone-to@betobtainedpincluding a'pluralty f of vertically adjustedknormally stationary bearing members defining a guideway for the sheet at the input thereof into the gap between the beam, means for adjusting the amplitude of the l movement towards the stationary beam as trans- Amitted by the motor to the second beam, a unidirectional clutch controlled by the electric motor and means controlled by said unidirectional clutch urging intermittently the sheet to be bent forwardly into the gap between the two beams and including a roller lying laterally of the movable beam in register with the gap between the beams, and a second roller revolubly carried by the stationary beam and adapted to cooperate with the first roller to produce the intermittent progression of the VSheet under the action of the motor in a manner such that the line of engagement thereof `with the two beams to either side thereof coincides at any moment with the location of a generating line of the cone to be obtained said sheet having an arcuate bottom edge.

16. A machine for bending sheet metal into a conical shape, comprising a stationary beam, a second beam substantially parallel with the first beam and defining therewith a narrow gap, an electric motor controlling the second beam and constraining it to assume a reciprocating movement towards and away from Y the stationary beam,means for adjusting the amplitude of the movement towards the stationary beam as trans- Lit- mitted by the motor to the second beam, a unidirectional clutch controlled by the electric motor and means whereby said unidirectional clutch urges intermittently the sheet to-be bent forwardly into the gap between the two beams and f including a roller lying laterally of the movable beam in register with the gap between the beams, a second roller revolubly carried by the stationary beam and adaptedv to cooperate with the first beam to produce the intermittent progression of vthe sheet under the action ofv the motor, a plurality of slotted members parallel with the general direction of the beam and located on the sheet input-side of the gap therebetween, and a roll fitted adjustably in the slot of each last mentioned member and adapted to define the position of the sheet passing into the gap before being bent in the latter said sheet having an arcuate bottom edge.

17. A machine for bending sheet metal into a conical shape, comprising a stationary beam, a second beam substantially parallel with the first beam and dening therewith a narrow gap, an electric motor controlling the second beam and constraining it to assume a reciprocating movement towards and away from the stationary beam, means for adjusting the amplitude of the movement towards the stationary beam as transmitted by the motor to the second beam, a unidirectional elutch controlled by the electric motor, means wherethrough said unidirectional clutch urgesI intermittently the sheet to be bent forwardly into the gap between the two beams and including a roller mounted on and projecting laterally of the movable beam and in register 1 vwith the gap between the beams, a second roller revolubly :carried bythe .stationary 4beam .and

9 adapted to cooperate with the rst roller to produce the intermittent progression of the sheet under the action of the motor, a plurality of slotted members parallel with the -beams and located on the sheet input side of the gap therebetween, a roll tted adjustably in the slot of each last mentioned member and adapted to dene the position of the edge of the sheet entering the gap before being bent in the latter, a carrier table extending laterally of the beam system, means for adjusting the angular setting of said table with reference to the gap, and rollers adapted to revolve round axes lying in a plane parallel with the surface of the table and over the latter and adapted to carry the lower edges of the sheets as they pass out of the gap between 10 the beams said sheet having an arcuate bottom edge.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 936,481 Scheld Oct. 12,1909 1,422,779 Perony July 11,1922 1,748,772 Hunker Feb. 25, 1930 2,426,260 Courtney Aug. 26, 1947 FOREIGN PATENTS Number Country Date 21,294 Great Britain ofi1896 409,548 Germany Feb. 6, 1924 516,273 Germany Jan. 21, 1931 

